Method of shaping and a series of shaping implements for slalom boots

ABSTRACT

A method is disclosed of shaping and a series of shaping implements for slalom boots, in which the slalom boot consists of a hard plastic outer shell and an inner boot manufactured from a flexible material. In accordance with the invention the boot is shaped to a perfect fit for the user as follows: a boot of the correct length is selected in accordance with the user&#39;s foot; the individual forms of the foot protruding from the boot are recorded; a point in the outer shell corresponding to each protrusion is shaped as follows: the point to be shaped is heated locally from the outside by hot-air blowing; the heated point is pressed from inside by means of a wooden piece, when the plastic material stretches and a protrusion arises.

TECHNICAL FIELD

This invention relates to slalom boots and more particularly to a methodof shaping and a series of shaping implements of slalom boots, in whichthe slalom boot consists of an outer shell made from hard plastic and aninner boot made from flexible material.

BACKGROUND ART

A slalom boot should transfer the movements of the foot precisely as aforce directed at the ski. On the other hand, a slalom boot should fitthe individual foot of the user without any feeling of cramping. Inaccordance with the known technique it is as such possible to shape aboot entirely in accordance with the user's foot by first choosing alarge outer shell and by fitting the inner boot to the shape of theuser's foot with the aid of urethane foam. Operationally a boot of thiskind is not, however, optimal, because the excessive flexibility of theinner boot reduces the technical operation of the boot.

In certain slalom boot models there are adjustments to alter the heightof the arch of the foot and to tilt the ankle to a limited amount to adesired angle. In any event the boot is not a perfect fit for most usersand it is generally believed that a slight cramping by the boot isnormal.

Because the costs of the forms used in the manufacture of the outershell are high, it is not possible to manufacture even different shapesin the same model and size. On the other hand even this would not besufficient, because there is such an immense number of combinations ofdifferent anatomical properties that a solution of this kind is notpossible.

A slalom boots and implements to shape it locally in accordance with theuser's foot are shown in patent publication U.S. Pat. No. 3,419,974.According to this a piece to be heated is pressed outwards from insidethe shell of the boot. In practice shaping of a boot with an implementof this kind is rather limited unless high temperatures are used inheating it, which may then damage the plastic material of the boot. Thegrades of plastic used at present in boots stick easily to a heatinghead. On the other hand the publication gives no hint as to how theanatomical form of the foot is transferred to the inside of the boot inthe form of directions for shaping.

DISCLOSURE OF INVENTION

An object of this invention is to create a method of shaping and aseries of shaping implements for slalom boots, by means of which a footwith nearly arbitrary properties can be fitted to existing slalom boots.

In carrying out the above object, the characteristic features of theshaping method in accordance with the invention are preformed on aslalom boot consisting of a hard plastic outer shell and an inner bootmade of flexible material. A boot of the correct length is selected inaccordance with the user's foot and the individual forms of the footprotruding from the boot are recorded. A point in the outer shellcorresponding to each protrusion is shaped by locally heating the pointto be shaped and pressing from inside the heated point, when the plasticmaterial stretches and a protrusion arises. The heating is carried outby hot-air blowing from outside and the internal pressing by means of awooden shaping head. The characteristics of a series of implementsdeveloped for the shaping of the outer shell of the boot consist of ahot-air blower, at least one pressing device and one or more woodenshaping heads to be attached to the pressing device. From the point ofview of the invention it is essential that it makes it possible toselect a boot of the correct length, after which the outer shell of theboot is given a shape fitting the foot. The shaping is mostadvantageously carried out with the aid of hydraulic pressing devices,in which wooden pressing heads are used. A wooden pressing head does notadhere to the plastic material, which would hinder the shaping. Otheradvantages and forms of application of the invention appear later.

In what follows the invention is illustrated with the aid of theaccompanying figures, which show one form of application of theinvention and advantageous series of implements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows the correction of a boot being carried out in accordancewith the present invention;

FIG. 1B shows a pattern made in accordance with a foot;

FIG. 2A shows a pressing device intended to shape the heel;

FIG. 2B shows a pressing head;

FIG. 3 shows the principal components of the series of shapingimplements;

FIG. 4 shows the hydraulic jack unit seen from the side;

FIG. 5 shows a third pressing device; and

FIG. 6 shows a cross-section of the pressing device in FIG. 5.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to the drawing figures, a slalom boot consists of a hardplastic outer shell 1 and inner boot made of flexible material. In FIGS.1A and 1B the outer boot is cut above the sole and the hydraulicpressing device 5 is placed inside the boot. The hydraulic pressingdevice 5 includes a pressing head 9 made from birch wood, which formsthe desired protrusion.

The shaping of the boot begins, however, with the measuring of the foot.The length of the foot principally determines the initial blank to beselected, which consists of an industrially manufactured slalom boot. Inaddition to the length of the foot its shape is also recorded by thepattern 2, which generally will not fit into a boot of the correctlength. A cut 3 is made in the cardboard pattern 2, by means of which itcan easily be bent to such an angle that it fits inside the outer shell1 of the boot to be shaped. The places to be shaped can then be easilylocated.

The place to be shaped is heated with a hot-air blower from both insideand out, when the plastic material softens, which makes it possible toshape it. With the aid of the hydraulic pressing device 5 the heatedplace is pressed by means of the wooden pressing head 9, when aprotrusion is created. After this the pattern 2 is once again comparedwith the shaped outer shell. It may require several shapings before thepattern fits the selected boot.

In addition to the individual sole profile there may be higherindividual features in the foot. Among other things the ankle bonesrequire their own corresponding protrusion in the outer shell.

A special device, shown in FIGS. 2A and 2B, has been developed forbroadening the heel. A pressing pair 10, which is spread with the aid ofhydraulic pressing device 6, is made from birch wood. Otherwise theshaping takes place as above.

By means of the series of implements shown in FIG. 3 it is possible tomake most of the protrusions required in the outer shells of slalomboots. A series of this kind includes a hot-air blower 4, a hydraulicpump unit 13, pressing devices 5, 6, 7, and pressing heads 9 adapted tothem. The pressing heads 9 are made form birch or other hard woodenmaterial. Birch wood has been shown to be especially well suited to thispurpose, because it is sufficiently hard and on the other hand it doesnot adhere to the heated plastic.

The pump unit 13 consists of a pump cylinder 12, FIG. 4, operated withthe aid of lever 11, valve 15 to direct the pressurized oil to one ofthe two exit connections 14, to which the pressing devices 5, 6, 7 areconnected. The pump unit 13 includes in addition an oil reservoir, andcounter and shut-off valves.

If the pressing devices in accordance with FIGS. 5 and 6 are used, theplace being shaped is determined in accordance with the heating point.Here the pressing device 8 includes two plates 16, 17 set a distanceapart and a flexible bag is placed between them, which when compressedpushes the wooden pressing heads 20 set in the outer ring outwardsagainst the inner wall of the boot. The pressing heads 20 are connectedto each other by means of the spiral spring 21 threaded through them.Pressurized oil is fed to bag 18 through connection 19. The pressure isequally great in all directions, but a change in shape takes place onlyat the point of the external heating.

The shaping in accordance with the above is naturally carried outseparately on each boot, from the measurement of the foot to the shapingof the boot.

While the best mode for carrying out the invention has been described indetail, those familiar with the art to which this invention relates willrecognize various alternative ways of practicing the invention asdefined by the following claims.

What is claimed is:
 1. A method of shaping slalom boots, consisting of ahard plastic outer shell and an inner boot made of flexible material, toconform with individual protrusions of a user's foot and comprising thesteps of:forming a pattern depicting the sole of the user's foot from aninflexible material; placing the pattern inside the boot; locallyheating a point corresponding to a protrusion in the pattern fromoutside the boot by hot-air blowing; and pressing the heated point frominside the boot using a wooden shaping head to stretch the plasticmaterial to conform to the protrusion in the pattern.
 2. The method ofclaim 1 wherein:the heating step is performed by a hot-air blower; thepressing step is performed by at least one pressing device; and whereinsaid wooden shaping head is attached to the pressing device.
 3. Themethod of claim 2 wherein:the pressing step is performed by a pair ofshaping heads intended to broaden the heel and a pressing device fittedbetween the shaping heads.
 4. The method of shaping of claim 2 whereinthe pressing step is performed hydraulically.
 5. The method of shapingof claim 2 wherein:the pressing step is performed using three roundedwooden shaping heads of varying lengths to make local protrusions. 6.The method of shaping of claim 2 wherein:the pressing step is performedby a pressing device including two spaced plates, a flexible bag withhydraulic fluid connections set between the plates and wooden piecessurrounding the bag and protruding between the plates, the extreme edgeof which is essentially the shape of a part of the sole.